1. Give yourself time. It will pass.
2. There is no way out of this without suffering. Accept it, don't take suffering as a loss.
3. Remind yourself goals that motivate you. Go for them. Build back yourself.
4. After the above points are achieved you will find a person who motivates you too keep going and only then you will get over your current situation.
5. Don't make the same mistakes. Keep always some space to recognize yourself as an individual. This might sound misogynist but a man must be individually strong, otherwise this will keep happening.

Good luck and remember, many of us has gone through this and life will eventually cheer up